Brake mechanism.



W. G. BAKER.

BRAKE MBGHAVNISM. APPLICATION FILED 00T.1s, 191s Patented Mar. 16, 1915.

2 SHEETS-SHEET 1.

W. C. BAKER.

BRAKE MEGHANISM. APPLIOATION FILED 001.13. 1913.

191 32,540. Patented Mar. 16, 1915-.

2 SHEETS-SHEET 2.

u w nu@ T33/Q55 OUGMQ `N f3 r g gu E Mijne/5555,'. XYZ/emv? ,f @@.Wmw y b imm/'mf WALTER C. BAKER, OF CLEVELAND, OHIO, ASSIGNOR TO THE AMERICAN BALL BEARING COMPANY, F CLEVELAND, OHIO, A CORPORATION 0F OHIO.

BRAKE MECHANISM.

Specification of Letters Patent.

Patented Mar. 16, 1915.

Application filed October 13, 1913. Serial No. 794,786.

To all whom t may concern:

Be it known that I, lVAL'raR C. BAKER, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in and Relating to v Brake Mechanism, of which the following is a specification.

This invention relates to brake mechanism, and particularly to that type of brake mechanism having a drum and a plurality of arc shaped brake members movable into and out of engagement with said drum.

One object of the invention is to provide a a brake mechanism which produces efiicient braking effects upon the application of a vrelatively small amount of power.

Another object of the invention is to provide, in a brake mechanism of this character supporting means which permit the brake members to accommodate themselves readily and quickly to the drum surface when operated.

Another object of the invention is to provide means for limiting the free movement of the brake members when they are in normal or inactive position.

Further obiects of the invention consist of' correlating the parts and causing them to co-act as hereinafter described and claimed.

YFor the purpose of illustration, I have, in the accompanying drawings, shown and described one form of brake mechanism embodying my invention.

Figure 1 is a fragmentary top plan view, partly in section, of vehicle axle and wheel having a brake mechanism embodying my invention. Fig. 2 is a section on the line 2-2 of Fig. l, looking in thedirection of the arrow. F ig. 3 is a section on the line 3 3 of Fig. l with the brake shoes retracted. Fig. 4 is a section on the same line as Fig.^3 with the brake shoes expanded. Fig. 5 is a detail view.

In the drawings` 1 indicates a vehicle wheel hub mounted on anti-friction bearings 2, 3 supported upon the outer end of an axle tube or casing 4.

5 is a driven axle section extending through the axle tube 4 and connected with the hub 1 by a clutch plate 6, this connection7being maintained by means of a hub ca I8J is a brake drum carried by the hub 1 i and rotatable therewith.

9 isa support for the brake shoes and their operating mechanism. It comprises .a i secured to the axle tube 4, a cyllndrlcal section 9a, incasing the tube cylindrical section 9 4 adjacent the inner end of the wheel hub, and diametrically opposed arms 9", 9, arranged between its said sections 9 and 9.

l0 isa packing gland between the inner iiange of the wheel hub and the support 9.

11 is an annular closure extending between the flange 9d and the inner surface of the brake drum 8, so as to practically close the inner end of the brake drum and prevent access of dirt pr dust to the brake mechanism in so far as practical manufacturing and operating limits permit.

I have illustrated two sets or couples of brake shoes, one at either side of the dialnet rically extending arms 9b, 9. As these sets are alike in construction, it will be necessaryl to describe but one ot them. Each set'of brake shoes comprises two arc shaped sec-V tions 12, 13. Their adjacent ends 12', 13', respectively, are provided with alined rectangular passage ways 12, 13, each ar ranged to receive a rectangular slide 14 which is pivotally mounted on a bolt 15 which extends through the arm 9. The bolt 15 at one end has a head 15. Its other end extends through an opening 11 in the closure 11 and carries a nut 16 and washers 17, 17.

18 is a coiled spiral spring interposed between t'he bolt head 15 and the washer 19. 18 is a similar spring interposed between the washers 17 and 19. These springs provide for necessary lateral movement in operation of the brake shoes, while tending to keep the shoes of both sets in normal position and to prevent rattling of the connected parts. The connection between each of the brake shoes and the pivot 15 is such as to permit the oscillation of each shoe' about the axis of the pivot 15 and the bodily move-- ment of each shoe to and fro relative to said axis.

The ends 12a', 13a', ofthe brake shoes substantially diametrically oppcsite the pivot 15 are free to move toward and from each other. They are normally drawn together by means of a spring secured at either end to the adjacent brake shoe. They are expanded into engagement with the inner surface of the drum through the instrumen- Atality of an expander or cam mechanism 20 are retracted or ininactive position.

35 to move the shoe, as

45 of brake shoes.

55 mentality of their expanding cam,

dicated as an entirety by 21. It consists of the pivotally mounted shaft 22 carrying a cam 23, the surfaces of which are ada ted to engage with the adjacent end sur aces 12", 13" of the brake shoes 12, 13, respectively. Each of these shoe end surfaces 1s rooyed as indicated at 24 to receive a rib v 5 on the cam.. rlhis tongue and groove construction serves to limit relative lateral movement of the shoes at their free ends within the drum. l

At its free end each brake .shoe carries -a dange 26, which if desired may be formed integrally therewith. Each flange 26 is recessed in the arc of a circle as indicated at Ithe recess at 26 is such that the greater the distance which the cam forces apart the ends ofthe brakeshoes with which it engages, the more up and down movement relatvev'to the cam shaft will be permitted 80 by the'iiange 26. On the other hand, when 'the brake shoe 1s retracted or drawn away from thedrum at its freehend, the -surface '2'6" apnroaches'quite closely to the periphery of thefcam shaft and may engage therewith i the case may be, up or down relative to the axis of the shaft 15 so as to ,insure thatthe shoe'will be free of the inner periphery of the brake 8 both at its top and bottom. The operatingl rod 22 for the expander for the outermost pair of brake shoes extends through the support or arm 9* inwhich it is pivotally mounted and loosely through the tubular shaft 22 for operating the expander for the innermost pair Any suitable mechanism (not shown) may be employed for actuating the rods or shafts 22 to rotate or oscil- .iate the cams 23 carried thereby, respectively.

lt'will be noted that my construction is such that the rake shoes of each set are i ermitted sufficient movement in various di- `rections relative to the drum to insure that when they are operated through the instruthey will freely and quickly accommodate themselves so'as tol engage considerable areas of the interior of the brake drum and that an elicotive braking action may be had with a relatively small angular movement of the cam.

Also. that when the brake shoes are released from the drum they are automatically7 drawn together at their free ends and at the same time if needs be are caused to slide on their 35 `respective guides 14 in such manner as to free from the drum at free themselves entirely at their pivoted ends lfrom the brake drum, through the instrumentality of the centering elements 26. In fact, the centering element 26 at the free end of each brake shoe insures that the shoe when drawn into inactive position will be all points.

To those skilled in the art of making apraratus of the class described, many alterations in construction and widely differing embodiments and applications of my invention will suggest themselves, Without departing from the spirit and scope thereof.

My disclosures and the description herein are purely illustrative, and are not intended to be in any sense limiting.

1. ln combination, a brake drum, a brake shoe, a pivot, a slide and guide connection between one end of said brake shoe and sai "pivot, said slide and its guide being mounted on said pivot to swing about the axis thereof, and an expanding cam disposed to engage the free end of said brake shoe.

2. In combination, a brake drum, a brake shoe, a pivot', a slide and guide connection between one end of said brake shoe and said pivot, said slide and its guide being mounted on said pivot to swing about the axis thereof, means for swinging' said brake shoe around the axis of said pivot into and out of engagement with said drum, and means for sliding said brake shoe relative to said ree aos

brake shoe as it is retracted and slide it' relative to the axis of the pivot.

4:. ln combination, a brake drum, a support, a'pair of opposed brake shoes arranged within said drum, means connecting adjacent ends of 'said brake shoes to said support including a pivot, a slide and a guide. and means interposed between the free ends or' said brake shoesl for expanding them about the axis of said pivot.

5. In combination, abrake drum, a support. alpair ot opposed brake shoes arranged within said drum, means connecting adjacent ends of 'said brake shoes to said support including a pivot, a slide and a guide, means interposed between the free ends of said bralreshoes for expanding them about the axis'o'f' said pivot, means for retracting the shoes, and means to engage said shoes as they are retracted and slide them relative to the axis of said pivot.

6. ln combination, a of opposed brake shoes,

brake drum. a pair a support for said each brake shoe to said support, permitting a rectangular slide in said guideway, a pivot both oscillation and sliding of said shoe between said slide and said support, and relative to said support, means for eXpandmeans for actuating` said shoe. ing and. retracting said brake shoes, and In testimony whereof Iax my signature,

5 meansfoperativ ais said bralke shoes move in the presence of two witnesses. away rom sai rum to si e said shoes relative to said support. WALTER C' BAKER' 7. In combination, a brake drum, a brake Witnesses: l shoe having a rectangular guideway formed GEO. B. PITrs, 10 in one end thereof, a support for said shoe, EDWARD R. ALEXANDER. 

